Assembly of a protected stopper and a test tube, said stopper being used for blood sample collecting or biological liquids handling test tubes

ABSTRACT

An assembly of a protected stopper with a test tube consists of a protected stopper for blood sample collecting or biological liquids handling test tubes which contains a substantially cylindrical inner body made of an elastomer, the body including a lower portion for insertion in a test tube, an upper abutment flange, and an abutment step formed between the inner body lower portion and the upper flange. The stopper also includes a substantially cylindrical cover made of a plastic for enclosing an upper part of the test tube and the inner body, the cylindrical cover including a free upper region for insertion of a sampling needle in the stopper and arc-like openings provided in the upper part. The engaging means provided in the cylindrical cover for engaging the inner body are constituted by arc-like protrusions which protrude from the inner wall of cylindrical cover which surrounds the lower portion of the inner body and couple with the abutment step, the protrusions being in an angular position which corresponds to the arc-like openings, a plan area of each one of the protrusions being entirely contained within a plan area of corresponding ones of the openings. The thickness of the cylindrical cover should preferably be 0.055-5.5 mm.

[0001] This application is a Continuation-in-part of U.S. Ser. No.09/339,861 filed Jun. 25, 1999

FIELD OF THE INVENTION

[0002] The present invention relates to a protected stopper for bloodsample collecting or biological liquids handling test-tubes.

BACKGROUND OF THE PRIOR ART

[0003] Protected stoppers for blood sample collecting or biologicalliquids handling test-tubes are already known. They are mainly composedof two parts:

[0004] an inner body made of rubber, which closes the test-tube and isadapted to be pierced with the needle of the syringe used to take theblood sample and/or with the needle of the syringe used for thesubsequent sampling required to perform a laboratory test;

[0005] a cover made of compact plastics, which encloses the rim of thetest-tube and the rubber body, performing a protective function for theperson handling the tube.

[0006] The compact cover is stably anchored to the inner body anddefines, in combination with said inner body in the region to be piercedwith the needle, a chamber for depositing any blood droplets leakingfrom the needle, so as to protect the operator by preventing him frommaking contact with it.

[0007] Several methods for anchoring one another said inner rubber bodyand the compact external cover are known.

[0008] In a first embodiment, the upper part of the cover correspondingto the region where the needle is inserted is fully open, but for asmall circumferential protrusion.

[0009] The internal body is provided with an external abutment step fora circumferential protrusion provided on the inner wall of the cover.

[0010] Assembly is performed by inserting the inner body in the cover,by elastic deformation, through the open upper part and by then placinga retention ring made of compact plastics between the small protrusionof the cover and the inner rubber body.

[0011] In this case, the stopper is formed by three parts (two main onesand one for mutually anchoring them); this entails the disadvantage thatassembly must be performed with two separate operations.

[0012] In a second constructive embodiment disclosed in EP 129,029, thestopper is actually made of two parts and the protective cover isinternally provided, in the wall that faces the inner body, with anannular groove in which a corresponding annular protrusion whichprotrudes from the internal rubber body is fitted.

[0013] From the point of view of production, the annular groove of thecompact cover defines an undercut which causes problems upon extractionfrom the injection mold from which it is obtained.

[0014] In fact the extraction of the core of the mold, which forms theinner hollow region and the annular groove, occurs by deforming the edgeof the annular groove and must be performed, in order to obtain anacceptable product, when the plastic material is still soft, i.e.,before hardening has occurred completely, and the thickness of the wallin which the groove is formed must be sufficient to deform and return tothe intended shape, after extraction from the mold.

[0015] This thickness of the wall causes a diametrical bulk whichconsiderably increases the corresponding diametrical dimensions of thetest-tube.

[0016] The diametrical dimensions of the annular protrusion of the innerbody also prevent mutual contact between the test-tube and the cover,leaving an empty space.

[0017] All this is constrained by the fact that the difference betweenthe overall diameter of the stopper and the diameter of the test-tubemust not be excessive, on penalty of making it impossible to insert saidtest-tube, when closed (assembled to the stopper), in correspondingseats provided in sampling accessories or adapters for analysisequipment, such as centrifuges.

[0018] The difference in diameter required in order to obtain athickness of the cover which is sufficient to allow to remove said coverfrom the mold increases with the diameter of the test-tube; accordingly,for example, for test-tubes having a diameter of 16 mm it has not beenpossible to provide a stopper according to the configuration shown in EP129,029 which could be accepted by the above mentioned laboratoryequipment.

SUMMARY OF THE INVENTION

[0019] The object of the present invention is to provide an assembly ofa protected stopper and a test tube. The protected stopper for bloodsample collecting or biological liquids handling test-tubes is composedof only two parts, an inner body made of elastomer and an external covermade of compact plastics, the external wall of the cover may be thin,that is slightly exceeding the dimensions of the test-tube, but this isnot essential.

[0020] Another object is to provide a protected stopper in which thecurrent production problems in terms of extraction of the cover from themold after injection have been eliminated.

[0021] A further object is to provide a protected stopper in which thecompact plastic cover is always in contact with the upper part of thetest-tube.

[0022] Still a further object is to provide a protected stopper whichcan be manufactured at a lower cost with respect to conventionalstoppers.

[0023] These objects and others which will become apparent hereinafterare achieved by a protected stopper for blood sample collecting orbiological liquids handling test-tubes, comprising:

[0024] a substantially cylindrical inner body made of an elastomer, witha lower portion adapted for insertion in a test-tube and an upperabutment flange;

[0025] a substantially cylindrical cover made of compact plastics, whichis adapted to enclose the upper part of said test-tube and said innerbody, leaving free an upper region for inserting the sampling needle;

[0026] said cover having means for engaging said inner body;

[0027] said stopper being characterized in that the engagement means areconstituted by arc-like protrusions which protrude from the wall of thecover that surrounds said lower portion of said inner body and couple tothe abutment step defined between said inner body and said upper flange.The protrusions are in an angular position which corresponds to arc-likeopenings provided in the upper part of the cover, the plan area of eachone of the protrusions being entirely contained within the plan area ofthe corresponding one of said openings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Further characteristics and advantages of the invention willbecome apparent from the detailed description of a preferred embodimentthereof, illustrated only by way of non-limitative example in theaccompanying drawings, wherein:

[0029]FIG. 1 is an exploded perspective view of a test-tube related tothe protected stopper;

[0030]FIG. 2 is a sectional perspective view, taken along a longitudinalplane, of the assembly of FIG. 1, in the assembled condition:

[0031]FIG. 3 is a sectional view of the assembly of FIG. 1, in theassembled condition;

[0032]FIG. 4 is a perspective view of the two components of theprotected stopper, taken along a sectional plane so as to clearlyillustrate their constructive details;

[0033]FIG. 5 is a top plan view of one of the two components of theprotected stopper, particularly the cover;

[0034]FIG. 6 is a sectional view of another embodiment of the stopper.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] With reference to FIGS. 1-5, this invention covers an assembly ofa protected stopper and a test tube. The protected stopper for bloodsample collecting or biological liquids handling test tubes comprises asubstantially cylindrical inner body (10) made of an elastomer. The bodyincludes an upper flange (13) and a lower portion (11) for insertion ina test tube (12). The test tube (12) has an upper part. The bodyincludes an abutment step (14) formed between the inner body lowerportion and the upper flange (13). The stopper also comprises asubstantially cylindrical cover (15) for enclosing the upper part of thetest tube and the inner lower body (10). The cylindrical cover (15) hasan upper part (18) and includes a free upper region (16) for insertionof a sampling needle in the stopper. Arc-like openings (19) are providedin the upper part of the cover. The means for engaging the inner bodyare constituted by arc-like protrusions (17) which protrude from aninner wall of the cylindrical cover which surrounds the lower portion ofthe inner body and couples to the abutment step (14). The protrusionsare in an angular position which corresponds to the arc-like openings(19). A plan area of each one the protrusions is entirely containedwithin a plan area of corresponding ones of the openings (19) so thatthe protrusions and the arc-like openings are vertically aligned. Theprotrusions are free of undercuts and have a radial dimensionsubstantially equal to the thickness of a test tube (12) which has anedge so that when the stopper is assembled to the test tube, theprotrusions are interposed between the abutment step (14) and the edgeof said tube.

[0036] The axial dimension of the flange 13 is of course substantiallyidentical to the distance between the protrusions 17 and the upper part18 of the cover 15.

[0037] As already stated hereinabove, the protrusions 17 are in anangular position that corresponds to arc-like openings 19 provided inthe upper part 18 of the cover 15, and the plan area of each one of theprotrusions 17 is entirely contained within the plan area of thecorresponding opening 19. In this manner the arc-like protrusions 17 donot constitute for the mold used for manufacturing, undercuts whichmight cause problems in extraction after molding.

[0038] It should also be observed that the inner body 10 is provided, inan upward region, with a recess 21 whose diameter is smaller than thediameter of the circular opening 16, so that it defines, on its own, achamber for collecting any drops of blood or of biological liquids thatmight fall from the sampling needle.

[0039] With reference to FIG. 6 which covers another embodiment, thisfigure shows an assembly of a protected stopper with a test tube, thestopper for blood sample collecting or biological liquids handling testtubes. The stopper comprises a substantially cylindrical inner body (10a), made of an elastomer. The body includes an upper flange (13 a) and alower portion (11 a) for insertion in a test tube (12). The test tube(12) has an upper part. The upper abutment flange (13 a) rests on theupper part of the test tubes. The stopper also comprises an abutmentstep (14 a) and a substantially cylindrical cover (15) for enclosing theupper part of the test tube and the inner lower body (10 a). Thecylindrical cover has an upper part (18), including a free upper region(16) for insertion of a sampling needle in the stopper. Arc-likeopenings (19) are provided in the upper part of the cover. Engagingmeans are provided in the cylindrical cover for engaging the inner body,which engaging means are constituted by arc-like protrusions (17 a)which have a triangular cross-section and which protrude from an innerwall of the cylindrical cover which surrounds the lower portion of theinner body and couples with the abutment flange (13 a). The protrusions(17 a) are free of undercuts. The abutment step (14 a) of the inner body(10 a) has radial dimensions such as to cause the rim region of the testtube (12) and the arc-like protrusions (17 a) to abut thereagainst, theprotrusions being external with respect to said rim region and have anupper part located with respect to an upper part of the cover at adistance which is substantially equal to an axial extension of theflange (13 a) of the inner body, wherein the arc-like protrusions have arectangular cross-section extension, so as to form a ledge.

[0040] This embodiment is provided by choosing appropriate dimensionsfor the diameters of the different components.

[0041] As regards operation, as already mentioned, the inner body 10 isassembled to the cover 15 by inserting it from the lower part until theflange 13 moves beyond the protrusions 17 and fits in the region betweenthe protrusions and the upper part 18.

[0042] It is then possible to insert the rim of the test-tube 12, whichplaces itself between the cover 15 and the lower portion 12 of the body10.

[0043] In practice it has been found that the intended objects of thepresent invention have been achieved.

[0044] In fact the cover 15 has no hollows in its cylindrical wall; ithas protrusions instead, and accordingly the only limitations to itsthickness are related merely to requirements of mechanical strength inuse and no longer to production needs. The thickness of the cylindricalcover may be 0.055-5.5 mm. Thus the test tubes may have a diameter ofboth 13 mm and also 16 mm.

[0045] Accordingly, its thickness can be minimal and therefore the totaldiametrical space occupation of the test-tube with the cover assembledthereon can be minimal too. Thus the test-tubes may have a diameter of13 mm and also 16 mm.

[0046] The structure of the cover 15 makes it possible that theprotrusions 17 are in any case not a problem for the molding operation.

[0047] The invention thus conceived is susceptible of numerousmodifications and variations, all of which are within the scope of theinventive concept.

[0048] All the details may further be replaced with other technicallyequivalent elements.

[0049] In practice, the materials used, so long as they are compatiblewith the contingent use, as well as the dimensions, may be any accordingto requirements.

[0050] The disclosures in Italian Patent Application No. PD98A000167from which this application claims priority are incorporated herein byreference.

What is claimed is:
 1. An assembly of a protected stopper and a test tube, said protected stopper for blood sample collecting or biological liquids handling test tubes comprising a substantially cylindrical inner body (10) made of an elastomer, said body including an upper flange (13) and a lower portion (11) for insertion in a test tube (12), said test tube (12) having an upper part, an upper abutment flange (13), said body including an abutment step (14) formed between said inner body lower portion and said upper flange (13), said stopper also comprising a substantially cylindrical cover (15) for enclosing said upper part of said test tube and said inner lower body (10), said cylindrical cover (15) having an upper part (18) and including a free upper region 16) for insertion of a sampling needle in said stopper, and arc-like openings (19) provided in the upper part of said cover, means for engaging said inner body, said engaging means being constituted by arc-like protrusions (17) which protrude from an inner wall of said cylindrical cover which surrounds said lower portion of said inner body and couples to said abutment step (14), said protrusions being in an angular position which corresponds to said arc-like openings (19), a plan area of each one of said protrusions being entirely contained within a plan area of corresponding ones of said openings (19), whereby said protrusions and said arc-like openings are respectively vertically aligned, said protrusions being free of undercuts, said protrusions having a radial dimension substantially equal to the thickness of a test tube (12), said test tube having an edge, whereby when the stopper is assembled to said test tube, said protrusions are interposed between abutment step (14) and said edge of said test tube.
 2. The stopper assembly according to claim 1 wherein said cover is always in contact with the test tube.
 3. The stopper assembly according to claim 1 wherein the axial dimension of said flange (13) is identical to the distance between said protrusions (17) and the upper part (18) of said cover.
 4. The assembly according to claim 1 wherein said cylindrical cover (15) has a thickness of 0.055-5.5 mm and is capable of operation with test tubes of external diameter 5-16 mm.
 5. An assembly of a protected stopper with a test tube, said stopper for blood sample collecting or biological liquids handling test tubes, comprising a substantially cylindrical inner body (10 a), made of an elastomer, said body including an upper flange (13 a) and a lower portion (11 a) for insertion in a test tube (12), said test tube (12) having an upper part, said upper abutment flange (13 a) resting on said upper part of said test tubes, said stopper also comprising a substantially cylindrical cover (15) for enclosing said upper part of said test tube and said inner lower body (10 a), said cylindrical cover having an upper part (18), including a free upper region (16) for insertion of a sampling needle in said stopper, and arc-like opening (19) provided in the upper part of said cover, engaging means provided in said cylindrical cover for engaging said inner body, said engaging means being constituted by arc-like protrusions (17 a) which have a triangular cross-section and which protrude from an inner wall of said cylindrical cover which surrounds said lower portion of said inner body and couples with said abutment, said protrusions (17 a) being free of undercuts, wherein said abutment step (14 a) of said inner body (10 a) has radial dimensions such as to cause the rim region of said test tube (12) and said arc-like protrusions (17 a) to abut thereagainst, said protrusions being external with respect to said rim region, wherein said protrusions (17 a) have an upper part located with respect to an upper part of said cover at a distance which is substantially equal to an axial extension of said flange (13 a) of said inner body, wherein said arc-like protrusions have a rectangular cross-section extension, so as to form a ledge.
 6. The assembly according to claim 5 wherein said cylindrical cover (15) has a thickness of 0.055-5.5 mm and is capable of operation with test tubes of external diameter 5-16 mm. 